Longest highways without a single concurrency

[gonealookin]

Nevada:
Interstate:  I-215, 12.796 miles (by default, no other candidates)
US route:  US 395A, 20.081 miles (also by default)
State route:  SR 318, 110.737 miles (in a squeaker over SR 140, 110.057 miles)

[US 89]

If the OP meant single routes end to end no matter what states, GA is definitely out, unless you count the small SPUR designations or small three digit rural highways.

GA 141 in particular comes to mind as a decent length example, with no concurrencies of any kind in its 34.1 miles.

It would take a long time to go through all of the state highways and check for overlaps, but there are a whole bunch of entirely independent routes even in more urban areas (though yes they are mostly short). Off the top of my head, in addition to 141 we also have 84, 237, 264, 279, 314, 317, 331, 347, and 378 in the Atlanta area with no overlaps of any kind along them.

[Crown Victoria]

Pennsylvania:

Interstate (and overall): I-476, 132.10 miles. Longest primary Interstate without an overlap is I-90 at 46.4 miles.
US Route: US 206, 0.46 miles. This is also the second shortest of any state, US, or Interstate route in PA, and the shortest one signed (PA 299 is the shortest, but unsigned).
State: PA 187, 43.13 miles

[SectorZ]

Massachusetts I believe would be I-90. MA 28 and US 20 are the only things longer and they have concurrencies with tons of things.

New Hampshire (and I had to look this up to confirm) is NH 175, just over 25 miles by itself. NH 110 is just behind it a half mile shorter.

For Mass., i-90 East has an unsigned concurrency with MA 1A from I-93 to its end in East Boston, but the first 133 miles are concurrency free. Then there's about 52 miles of I-95, excluding the 128 concurrency.

I thought MA 1A went through the Callahan/Sumner tunnels and would stay on 93/1/3 as a silent concurrency with its parent up to the junction. Otherwise, 495 would be the longest in MA.

You and I thought that because it does.

[SEWIGuy]

I-794 is the only Interstate in WI that qualifies (3.5 miles).
All of the US routes have a concurrency at one point.
The longest state route without a concurrency could very well be WI-153 (61 miles).

WI-153 has a "hidden" concurency with Marathon County J east of Mosinee.  Wisconsin has a lot of those with county highways.  Are those actually concurrencies if they aren't signed?

[thspfc]

I-794 is the only Interstate in WI that qualifies (3.5 miles).
All of the US routes have a concurrency at one point.
The longest state route without a concurrency could very well be WI-153 (61 miles).

WI-153 has a "hidden" concurency with Marathon County J east of Mosinee.  Wisconsin has a lot of those with county highways.  Are those actually concurrencies if they aren't signed?

Didn't even think about concurrencies with county highways.

There's an odd one on CTH-CV in Windsor. It runs eastward along WI-19 for a mile to US-51, then it turns south onto US-51 for 1.5 miles. It is (subtly) signed at the 51 and 19 interchange: https://www.google.com/maps/@43.1946114,-89.3262852,3a,15y,102.24h,89.47t/data=!3m6!1e1!3m4!1s8I9fiVaE39hM-uS7fgAohw!2e0!7i16384!8i8192

https://www.google.com/maps/@43.1946114,-89.3262852,3a,15y,102.24h,89.47t/data=!3m6!1e1!3m4!1s8I9fiVaE39hM-uS7fgAohw!2e0!7i16384!8i8192

[Big John]

^^ There is CTH K i Waupaca County which has a silent concurrency with US 10/WI 22,49,54.

[US 89]

Massachusetts I believe would be I-90. MA 28 and US 20 are the only things longer and they have concurrencies with tons of things.

New Hampshire (and I had to look this up to confirm) is NH 175, just over 25 miles by itself. NH 110 is just behind it a half mile shorter.

For Mass., i-90 East has an unsigned concurrency with MA 1A from I-93 to its end in East Boston, but the first 133 miles are concurrency free. Then there's about 52 miles of I-95, excluding the 128 concurrency.

I thought MA 1A went through the Callahan/Sumner tunnels and would stay on 93/1/3 as a silent concurrency with its parent up to the junction. Otherwise, 495 would be the longest in MA.

You and I thought that because it does.

I thought there was something about 1A being rerouted to I-90 because the I-93 tunnel lacks some movements to/from the Sumner/Callahan tunnels that the old Central Artery had.

[DJDBVT]

Vermont:

I-91 (177.4 miles)
US 4 Business (4.3 miles)
VT 102 (43.7 miles)

[Flint1979]

I-794 is the only Interstate in WI that qualifies (3.5 miles).
All of the US routes have a concurrency at one point.
The longest state route without a concurrency could very well be WI-153 (61 miles).

WI-153 has a "hidden" concurency with Marathon County J east of Mosinee.  Wisconsin has a lot of those with county highways.  Are those actually concurrencies if they aren't signed?

Didn't even think about concurrencies with county highways.

There's an odd one on CTH-CV in Windsor. It runs eastward along WI-19 for a mile to US-51, then it turns south onto US-51 for 1.5 miles. It is (subtly) signed at the 51 and 19 interchange: https://www.google.com/maps/@43.1946114,-89.3262852,3a,15y,102.24h,89.47t/data=!3m6!1e1!3m4!1s8I9fiVaE39hM-uS7fgAohw!2e0!7i16384!8i8192

https://www.google.com/maps/@43.1946114,-89.3262852,3a,15y,102.24h,89.47t/data=!3m6!1e1!3m4!1s8I9fiVaE39hM-uS7fgAohw!2e0!7i16384!8i8192

I was trying to figure it out but gave up lol.

[74/171FAN]

Pennsylvania:

Interstate (and overall): I-476, 132.10 miles. Longest primary Interstate without an overlap is I-90 at 46.4 miles.
US Route: US 206, 0.46 miles. This is also the second shortest of any state, US, or Interstate route in PA, and the shortest one signed (PA 299 is the shortest, but unsigned).
State: PA 187, 43.13 miles

It was so difficult for me to think what PA route may be.  I used to think that PA was the haven of short concurrencies until I started clinching a lot more roads in OH this year.

[Molandfreak]

MN

I-: none
US: none
MN: MN 61 (149 miles)

Technically there's a concurrency with Cook County 17. 

And US 69 in MN doesn't have a concurrency.

[DandyDan]

MN

I-: none
US: none
MN: MN 61 (149 miles)

Technically there's a concurrency with Cook County 17. 

And US 69 in MN doesn't have a concurrency.

Neither does US 65, unless county highways count.

[kenarmy]

MS

US: US 90 (~80 miles)
I: I-110 (~5 miles, MS 15 was truncated from the concurrency recently)  (I-269 is 26 miles if you don't count MS 304)
SR: Idk. But MS 53 is 38.9 miles and it doesn't have a concurrency.

[TheHighwayMan3561]

MN

I-: none
US: none
MN: MN 61 (149 miles)

Technically there's a concurrency with Cook County 17. 

And US 69 in MN doesn't have a concurrency.

Neither does US 65, unless county highways count.

65 is also duplexed with BL I-35 in Albert Lea, if that means anything.

[odditude]

For New Jersey...

I believe the GSP wins in NJ, at 88 miles (around MP 84 to MP 172 at the NY State border).

If you wanna get technical with the wording "longest highway", the NJ Turnpike, as a highway, doesn't have a concurrency for 117 or so continuous miles, with its sole concurrency being from MP 0 to MP 0.9 with US 40.  The remainder of the highway has two different route numbers, but they never overlap.

i believe the intent is full highways without a concurrency (as opposed to longest highway segments without).

based on that criteria, based on a quick scan of Wikipedia:

ACX - 44.19 mi
NJ 55 - 40.54 mi
I-195 - 34.17 mi
US 9W - 11.17 mi

[jp the roadgeek]

Massachusetts I believe would be I-90. MA 28 and US 20 are the only things longer and they have concurrencies with tons of things.

New Hampshire (and I had to look this up to confirm) is NH 175, just over 25 miles by itself. NH 110 is just behind it a half mile shorter.

For Mass., i-90 East has an unsigned concurrency with MA 1A from I-93 to its end in East Boston, but the first 133 miles are concurrency free. Then there's about 52 miles of I-95, excluding the 128 concurrency.

I thought MA 1A went through the Callahan/Sumner tunnels and would stay on 93/1/3 as a silent concurrency with its parent up to the junction. Otherwise, 495 would be the longest in MA.

You and I thought that because it does.

I thought there was something about 1A being rerouted to I-90 because the I-93 tunnel lacks some movements to/from the Sumner/Callahan tunnels that the old Central Artery had.

Executive Office of Transportation - Office of Transportation Planning Roads - June 2008: The older tunnels to and from East Boston have interchanges with I-93 and surface roads north of the point at which unsigned Route 1A "exits" Route 1 in downtown Boston. Unsigned Route 1A along the Fitzgerald Expressway does not directly connect to those tunnels; a direct connection requires using I-90 and the newer Ted Williams Tunnel, which is not concurrent with Route 1A at any point.